Improvement in gas-motor engines



'2 Sheets-Sheet 1. N. A. OTTO.

GAS MOTOR ENGINE.

NJEIENS, PIQTOYUTHOGRAPHER. WASHINGTON. D, C.

GAS MOTOR ENGINE. No..178,023. Patented May 30,1876.

| I I I IIHIIIHIIII" A v:

,UNITED STATES PATENT, OFFICE nrooLAUsAUGUsT OTTO, OFDEUTZ, GERMANY. I

IMPROVEMENT IN GAS-MOTOR ENGINES.

Specification forming part of Letters Patent No. 178,023, dated May 30, 1876; application filed January 1l0, 1876.

To all 'whom .it 'may concern: l

Be itknown that I, NtcoLAUs AUGUST OTTO, of the Gas-Moteren Fabrik-Deutz, at Deutz, in the Empire of Germany, have invented an Improvement in Gas-Motor Engines; and do hereby declare th at the following description, taken in connection with the accompanying sheets of drawings, hereinafter referred to, formsa full and exact specification of the same, wherein l haveset forth the nature and principles of my said improvement, by which my invention may be distinguished from others of4 a similar class, together with such parts as I claim and desire to secure by Letters Patentthat is to say:

My invention relates to gas-motor engines of that kind in which a mixture of combusti- Vble gas and air is ignited within a cylinder,

the explosion propelling aloose piston without doingwork; and then, as the products of combustion contract by cooling, reducing the 4pressure within the cylinder, another piston is forced inward by the excess of atmospheric pressure, and this piston, being connected to cranks on a fly-wheel shaft, gives, during its instroke, an impulse to the rotation of thel shaft, which is utilized as motive power. A1

portion of the power thus developed may also,

` according to the construction which I will de-` scribe, be applied to the pumping or forcing of water or otherl liquid.

In engines of the kind referred to, it has been usual to apply clamps, friction-clutches, ratchets and pawls, or other mechanical devices, for the purpose of holding at suitable times the loose piston, or, in some forms of such engines, for alternately connecting one piston to the rotating shaft, and disconnecting it therefrom, so as to make this piston act in i the double capacity of loose and working piston.

The object of my invention is to dispense with such mechanical devices, which have proved a source of difficulty in the construction of such engines, and of rapid wear in their Orking, and to substitute for Athem the hyflldraulic action ot' water or other liquid, as I u ill now describe, referring to the accompanying drawings, of which- Figure 1 represents a longitudinal section,

` and Fig. 2 a plan, of a gas-motor engine according to my improved construction.

A is a water-jacketed cylinder, open at both ends, and fitted with a working piston, a,

which is connected by a cross-head and side rods to crank-pins on two fly-wheels, W W,

keyed on a shaft, S. In the same cylinder is fitted a loose piston, B, which is connected by a rod, b," to a piston, c, fittedl ina hydraulic cylinder, G. On the side of the cylinder A, near its outer end, is fitted a slide, D, such as is usually employed in engines of the kind referred to above, Worked by an eccentric, d," for the admission of the combustible gaseous mixture and the igniting-flame to the cylinder A.

There is also provided, near the inner end of the cylinder A, an outlet-opening, O, fitted with a valve openin g outward, for the issue of the products of combustion from the'eylinder. The hydraulic cylinder C has a side passage, P, communicating from the one end to the other, and is provided at its outer end with a suction-pipe and valve, E, opening inward with a valve, F, which is free to open upward, tending to close of itself when there is excess of pressure 011 its upper side, but which can be raised from its seat by a bell-crank lever, f, worked by a rod, f from a lever, g, operated Aby a cam, Gr, on the fly-wheel shaft S in the one direction, and by a spring, R, in the other direction. Above the valve F is a dischargevalve, H, opening outward, which can be held `down more or less closely to its seat by a screwed spindle, worked by a hand-wheel, h.

I will first describe the working of the engine when the valve H is held down ou its seating, the hydraulic cylinder C and its passage P beingfully charged with water, oil, 'or

other suitable liquid.

I will assume that the working piston a has, by the revolution of the iiy-wheels, been brought to the extreme of its outstroke, as indicated by the dotted lines a, the loose piston B having been arrested in the position E', so that the space between a and Bhas received a charge of the combustible gaseous mixture. This mixture being ignited the piston B is propelled inward, and, in case of its tending to move ltoo far, is checked by a ring, X, provided with elastic buffers a'. As B is thus propelled it forces the piston c outward, and displaces the liquid in the hydraulic cylinder G by causing it to flow from the outer end of the cylinder past the valve F, which opens for its p the valve F to rise from .its seat, so

passage, along the conduit P to the inner end of the cylinder. The loose piston having been thus propelled to B, just past the outlet'O, the gaseous products in the cylinder A tend to contract by their-cooling, and thus the pressure within the cylinder is reduced below that of' the external atmosphere.

The excess of external pressure now tends to force back the piston B, but it is held stationary by its connection to the piston c because the valve F closes and prevents-the liquid fromflowing back to the outer. end of the cylinder C; The external pressure therefore forces the piston a inward, and its movement gives an impulse to the ily-Wheels. As

the piston c approaches B the gaseous products of combustion in the space between the two pistons become compressed; but the momentum of the ily-wheels continue the inp stroke of' a, so that these products are forced out by the outlet O. The piston a, having thus come close up to B, the cam G causes as to give free passage for the liquid from end to end of the hydraulic cylinder C. The piston a, being now caused by the momentum of the fly-wheels to make its outstroke, the piston B follows it. The cam G is, however, so formed and set that when B has got to the position B the valve F is permitted to close, stopping the loose pist-on at B. The piston a now continuing its outstroke to a', a charge of the combustible gaseous mixture is drawn through the slide D into the space between a and B', and the igniting-flame being also drawn in, the mixture is exploded, whereupon the action is repeated, as already described. According to this mode of working the whole of the power developed is transmitted to the iiy-wheel shaft, and for an engine intended to work in this manner the suction and discharge pipes and valves E and H may be dispensed with.

I will now describe a mode of operating whereby a portion of the power is applied to pumping or forcing liquid. This is effected by turning 'the hand-Wheel h, vso as to give the valve H freedom to rise more or less from its seat. When this is done the piston c, during its instroke or movement toward the shaft S, draws in a portion of the liquid by the suction-valve E, and discharges a portion of the liquid contents of the cylinder by the valve H, the opening of the valve F being adjusted by varying the throw of the cam G, or, more simply, by

altering the length of .the rod Yof a liquid in a f1 by an adj ustingnut, f2, so as to permit les or more of the liquid to pass it from P to th outer end of the cylinder C duringthe instrokl of c. When the engine operates in this manne: the pistons c and B are'not held stationary during the instroke of a, enter by the valve E and issue by EI 5 bul While a is making its instroke, B makes part -of an outstroke to meet a, and then, the momentum of the fly-wheels carrying a onward,

B is pushed back and the products of combustion are discharged atO, as already del scribed. Moreover,-while c is making its .because liquid can outstroke, B following, it is not absolutely* stopped in the position B by the liquid in C, which is free to flow by the valves E and H, but it naturally stops when the gaseous mixture is admitted by D, pheric pressure on B anced.

Having thus described the nature of my: know of carinto practical operation, I`

invention, and the best means I rying the same claim- In gas-motor engines, wherein a combustible gaseous mixture is exploded without doing work, and the contraction of the products of combustion due to cooling is utilized for y producing motive power- 1. The method of alternately arresting and permitting the i movement of a piston by regulating the liow tially in the manner herein set forth: 2.

loose piston B with a piston, c, Working in a hydraulic cylinder provided with passage P and valve F, operated by a cam, Gr, substantially and for the purposes bination of the loose c, working in a hydraulic cylinder having passage P and valve F, operated by a cam, G, with. the suction-valve E and adjustable discharge-valve-H, for the purpose of utilizing part of the motive power for pumping or forcing liquids, substantially as herein described, with reference to the accompanying drawings.

In testimony whereof two subscribing November. 1875.

N [COLAUS AUGUST OTTO.

Witnesses GUs'rAv KLEINJUNG, FRIEDRICH ALBERT SPIECKER.

witnesses, this ninth day ot' because the atmosis then counterbalhydraulic cylinder, substani The combination of the f as herein described, with reference to the accompanying drawings: 3. y The compiston B and piston' I have signed my' name to this specification in the presence of 

